A Will-O-Wisp is a phenomenon often described as a ghostly light that appears at night, typically over marshy or swampy areas. These lights are usually blue or green and can lead travelers off their paths, creating an eerie and mysterious atmosphere. The term is derived from folklore, where they are often associated with spirits or fairies. Scientifically, Will-O-Wisps are thought to be caused by the combustion of gases released from decaying organic matter in wetlands. This process can produce small flames or glowing lights that resemble the mythical lights. While they have captured the imagination of many cultures, their natural explanation helps demystify this intriguing phenomenon.